1. Field of the Invention
The subject invention relates generally to a vehicle seat having an integral safety restraint system, and more particularly to such a vehicle seat including an improved structural design capable of withstanding high impact loading without jeopardizing structural integrity or occupant safety.
2. Description of Related Art
Vehicular, and in particular automotive, seat assemblies are becoming increasingly unitized so that they can be rapidly and easily installed as a modular component in the passenger compartment via an assembly line type operation, thereby reducing vehicle assembly time and the assembly line personnel required to complete the installation. One such adaptation toward this end has been the integration of a safety restraint belt with the seat assembly. In this manner, the seat assembly together with the safety restraint belt are installed as an integral unit in the passenger compartment at the time of vehicle manufacture.
One important consideration when the safety restraint belt is integrated with the seat assembly becomes the strength and integrity of the seat assembly components so as to withstand the severe loading which may occur in emergency situations of sudden deceleration, such as may occur in a collision. Sudden deceleration creates elevated forces resulting from the mass of a seated and restrained occupant tending to remain in motion, while the vehicle rapidly decelerates. Under these conditions, when the safety restraint belt is rapidly tensioned by the momentum of an occupant, the restraining forces are transmitted through the safety restraint belt to its points of connection with the seat assembly, which usually comprise at least two connection points on the bottom frame (for a lap strap segment) and either a connection point or pulley on the backrest frame (for a shoulder strap segment). These forces travel from the connection points, through the various structures in the seat assembly, and finally to the locations at which the bottom frame is anchored to the floor of the passenger compartment. Each and every structural component through which forces flow during periods of severe loading must be adequately designed to prevent unnecessary injury to the occupant.
Furthermore, the seat assembly must be properly designed to allow free flowing movement of the safety restraint belt as it is played out and reeled in. It must not snag or cause binding in the safety restraint belt in any way. The subject invention is directed at providing a seat assembly with an integrated safety restraint belt which is capable of withstanding severe loading resulting from sudden deceleration, which is easily and quickly installed in the passenger compartment of an automobile during manufacture, and which does not cause binding or snagging of the safety restraint belt.